
Ant-mimicking crab spider crushing an ant, Orito, Colombia
Genus Bucranium, which only has 4 species. Through exclusion of appearance and distribution, Bucranium taurifrons seems most likely, but there's hardly any photos of the 4 species, most seem to leave it at the genus level, except for this one:
https://www.flickr.com/photos/55321611@N07/6302986155
Bucranium taurifrons is also the genus' type species and until recently, the only species in the genus. As it is most often reported and the distribution roughly matches, I'm going for the type species for now.
Also interesting is that the Bucranium genus is split from the Aphantochilus genus. Be sure to search for Aphantochilus for some more incredible ant mimicking spiders!

''Bucranium taurifrons'' is a species of ant-mimicking crab spiders from South America. It is found in Venezuela, Guyana, Peru, Brazil and Paraguay.
Like the crab spider ''Aphantochilus'', it mimic ants of the genus ''Cephalotes'' , which are their preferred prey. It also carries dead ants.